This is a quick overview, not a comprehensive dissertation. Goggle it if you need more info.

There was unprecedented growth in new gun ownership in 2020 with some 2+ million new owners in just December alone. If each person wanted just one box of ammo (50rds) for their new pistol, you would need 100 million rounds to satisfy the demand, which depleted available stocks and exhausted the supply chain. Manufacturers went to 24/7 production, but capacity and component shortages haven't helped.

Fast forward to the internet age and the question why online retailers like Midway, Brownells, MidSouth, Powder Valley, Brunos, Ammo Land or any of your preferred suppliers don't have stock. Well, they do, you just don't see it before it's gone, even if you've signed up for email notifications.

• The Tier 1 IT types are using "bots" to receive in stock notifications and buy up the supplies (and most likely resell them on Gunbroker). A bot is (as one example) a software program coded to look at the price or availability section of a web page and when it changes, for example from out-of-stock to in stock, send an immediate notification to the programmer, who then hits the site and buys the item before anyone else. The millisecond Brownells lists CCI small rifle primers on their site, the bot sends a message to their masters and boom, they're gone.
• The Tier 2 people have started groups on IT servers where they share bot results so they too have an immediate pipeline to in stock components. The bot results are shared (probably after the bot owner buys what they want) with the members on the server so they have almost immediate availability to in stock components.One of the prominent reloading component servers is Discord, which started with a few hundred people, but now has thousands of 103,000 people following in-stock notifications.
• The Tier 3 folks sit at their computers all day with their 10 managed alerts from AmmoSeek active, as well as a dozen different supplier webpage windows open hoping they refresh a page at the right time to find some stock.
• The Tier 4 people are still waiting on an in-stock notification email and thinking they should be able to find ammo and components at their favorite site but haven't see anything (affordable) since before October.

Rinse and repeat the above for any item from 22LR to brass, bullets and other components. The sellers are attempting to fight back but it's like trying to stay a step ahead of the Nigerian scammers. MidSouth now scans for bots and if they find any they ban the IP address of the programmer. Others are simply limiting how much you can buy, which, by the time you add in hazmat, shipping and taxes, drives prices even higher for small lot purchases. The Tier 1 IT types are also getting craftier, they now have bots that "steal" items from your cart and puts the items into theirs. So, you've made it through the 5 steps and you hit enter for a confirmation and boom, you get a notice saying you don't have anything in your cart. Tactics are evolving but the results are the same, suppliers are trying, middlemen are marking up all components, speculators are reselling at exorbitant prices and the rest of us are all scrambling to find anything to shoot.